Finding the Third Proportional to 216,123 and 311,329.50

Step by Step Solution

1. Step 1: Write the proportion equation
   216,123 : 311,329.50 = 311,329.50 : x
2. Step 2: Convert to fraction form
   216,123/311,329.50 = 311,329.50/x
3. Step 3: Cross multiply
   216,123x = 311,329.50 × 311,329.50
4. Step 4: Simplify right side
   216,123x = 96,926,057,570.25
5. Step 5: Solve for x
   x = 96,926,057,570.25/216,123
6. Step 6: Final answer
   x = 448,476.37